Circuit breaker for fire alarms



March 15, 1932. PRATURLON 1,849,551

CIRCUIT BREAKER FOR FIRE ALARMS Filed Feb. 25. 1929 l I INVENTOR. 7 3Q 7 UNITED STATES PATENT OFFICE EMILIO PBATUBLON, OF REDWOOD CITY, CALIFORNIA CIRCUIT BREAKER FOR FIRE ALARMS Application filed Fehruary 2a. 1929. Serial no. 342,140.

The invention forming the subject matter of this application relates to thermo-responsive circuit breakers and particularly to circuit breakers or switches used in connection with fire alarms or the like.

The primary object of the invention is the provision of a normally open switch which is resiliently held in the open position thereof by a thermo-responsive element, which elem ment reacts to high temperaturein such a manner as to release the open element of said circuit breaker and permit the automatic closing thereof, whereby the electric circuit of the signal is readily completed.

Another object of the invention is the provision of a circuit breaker, themovable element; of which is held in a circuit breaker or switch opening position by a temperature responsive element, said last element being so formed as to'burst at a high temperature, such as caused by fire; the movable switch element is held in the open position by the rigidity of said temperature responsive ele ment, resilient means being provided to move the said movable switch element into closing position after thebursting of the temperature responsive switch element.

Other objects and advantages of the invention are to provide a thermo-responsive circuit breaker that will be superior in point of simplicity, 'inexpensiveness of construction, positiveness of operation, and facility and convenience in use and general efficiency.

In this specification and the annexed drawings, the invention, is illustrated in the form considered to be the best, but it is to be understood that the invention is not limited to such form, because it may be embodied in other forms; and it is also to be understood that in and by the claim following the description, it is desired to cover the 'inventionin whatsoever form it may be embodied.

The invention is clearly illustrated in the 5 accompanying drawings in which,

- Fig. 1 is a side elevation of the circuit breaker;

Fig. 2 is a front view of the circuit breaker constructed in accordance with my invention Fig. 3 is a sectional detailed view of the temperature responsive element of the circuit breaker;

Fig. 4 is a fragmentary sectional view, the secgion being taken on the line 44 of Fig. 2; an

Fig. 5 is a wiring diagram showing the connection of the circuit breaker with a source of electricity and with the signal.

In carrying out my invention I make use of a board, being designated by the numeral 6, 0

screw 9 extends through the baseboard 6, the

head thereof engaging the rear face of said baseboard so as to allow the drawing up of the knob 8 and the plate 7 therewith, against the front face of the baseboard 6. Into a transverse slot 11 on said knob 8 is pressed a double end of a bracket 12 is bent at right angles, and the upright member 13 thereof has a pivoted screw 14 movable therein-for the purpose of pivotally supporting a movable contact lever 16 of the circuit breaker. In order to connect this lever 16 to one terminal of a source of electricity, a terminal post 17 is provided adjacent to the free end of the plate 7 to which an electrical conduit 18 is secured in the usual manner. As. it will be noted in Fig. 5, the conduit 18 is connected to a terminal of a battery 19.

It is to be noted that the opposite ends of the lever 16 have ears 21 and 22 formed thereon extending axially and at right angles to the plane of the lever 16. In the path of the movement of the end of the lever 16 on which the ear 22is formed, is disposed another plate 23, which is secured to the front face of the baseboard 6 in a manner identical with the attachment of the plate 7. In the retaining knob 8 of the plate 23 is secured a stationary contact member 24. The member 24 is dis- 12. The bracket lever 16. In

posed in a slanting position so that when the lever 16 is turned in the direction of said contact member 24, the car 22 on said lever a. socket 29 by means of a screw 31. In the of the socket 29 is formed a conical seat to? receiving a tube 32 thereinto. The tube is elongated and the ends thereof terminate in the usual conical point one of which readily seats itself in the corresponding seat in the socket 29. In order to prevent the upward movement of the tube 32, the upper end of the tube 32 abuts against a stationary socket 33 mounted on a bracket 34, which bracket in turn is attached to the baseboard 6 in the manner shown in Fig. 1.

The pivot 14 is disposed at one side of the vertical center line of the lever 16. In order to firmly hold the tube 32 in place, the end of the lever 16 upon which the ear 21 is located, must be forced upwardly and this action is accomplished by a tension spring 36, an end of which spring 36 is attached to the baseboard by means of a suitable screw 37 while the other end of the said spring engages the lever 16 at a point between the pivot 14 and the ear 22. Thus, the action of the tension spring 36 urges the lever 16 to move ina clockwise direction, viewing Fig. 2. When the tube 32 is in place, the action of the spring 36 forces the socket 21 against the bottom of the tube 32 but the said tube 32 prevents the turning of the lever 16 and the contacting of the same with the member 24.

The tube 32 is filled with a fluid 38. The fluid may be of any suitable temperature responsive mixture which rapidly expands under the action of heat, such fluid may be alcohol, ether, or the like. The tube is pref.- erably made of glass or other suitable mate- 'rial and of such thickness that it cannot withstand the bursting pressure caused by the expansion of the fluid therein, under the effect of heat. The strength of the tube 32 and the quantity of the fluid 38 will determine the actual temperature -at which the circuit breaker is actuated.

In operation, the circuit breaker is connected in an electric circuit in the manner-shown in the wiring diagram in Fig. 5. An alarm si al such as a bell 39, is connected in series wlth the electrical conduit 27. The circuit breaker is held normally open by the tube 32 which prevents the pivotal movement of the the event of fire, there is an undue rise of temperature in the room where the fire occurs, which will cause the expansion of the fluid 38 and the bursting of the tube 32. After the bursting of the tube 32, the action of the tension spring 36 moves the lever 16 around its pivot 14 so that the ear 22 is brought into contact with the member 24, whereby the circuit is completed from the conduit 18 to the conduit 27. Being that the alarm signal, such as the bell 39, is connected in series with the conduit 27 the flow of electric current, after the circuit breaker is closed, causes the operation of the signal,

in the present instance, the ringing of the bell. Thus attention is called to the fire.

It will be recognized that a particularly compact device is provided to automatically actuate a fire alarm signal and it will be also recognized that the signal may be disposed at a remote point from the circuit breaker itself or at any suitable point where it may be readily observable; the device is compact, and combines simplicity of operation with ruggedness of construction which readily adapts the same for its use. The device is of 'a unitary character, does not require any adjustment or setting up, the only manual operation required in connection therewith is the replacement of the tube 32 which may be readily effected by turning the lever 16 against the action of the spring 36 and inserting the tube 32 operation. i

Having thus described this invention, what I claim and desire to secure by Letters Patent is:

A circuit breaker comprising a base, a stationary contact on the base connected to a source of electricity, a lever pivotally mounted intermediate its ends on said base and connected to said source of electricity, a contact formed on an end of said lever in operative relation to the stationary contact, a socket on the other end of the lever extending in a direction opposite to the lever contact,

another socket on the base above and opposite to said socket on the lever, a tube disposed between said sockets, said tube containing a substance adapted to burst the tube under the eilect of a certain heat, and a spring on the base connected to the lever between the pivot of the lever and the said lever contact "to normally urge the lever toward the station- V in its place, then by releasing the lever 16, the circuit breaker is ready for 

